Propeller.



. GIBSON.

PROPELLER. APPLICATION FILED IuNE 4,19Io.

Patented July 20, 1915.

" IIL INVENTOR TM/rhgo @idf wI'TNEssEs 9M ATTORNEY ARTHUR HUGO CECIL GIBSON, 0F NEW YORK, N. Y.

'.PRQPELLER.

and its object is to improve upon the method of manufacture of such devices, and'to pro vide a propeller of great strength and with but little weight.

I will describe my invention in the following specification and point out the novel features thereof in the appended claims.

Referring to the drawings, Figure 1 is a plan view of a propeller made according to my invention. Fig. 2 is aplan view of the same propeller showing it as it appearslin one of the steps of the process of its manufacture. Fig. 3 is a sectional end elevation on an enlarged scale of the propeller in the condition it is in in Fig. 2. Fig. 4 is a plan View of a modified form of propeller. In Fig. 5 have shown in sectional end elevation a textile band which is used. in making propellers according to this invention.

Like characters of reference designatey corresponding parts in'all of the figures.

10 designates the hub of the propeller, and

F11 its blades. These parts yare built up of layers or laminations of fibrous material such as wood. The grain in these pieces is arranged to lie lengthwise 4of the propeller. Alternate layers of mahog ny and ash give satisfactory results. v

According to my invention each of the parts which is to be one of the layers lis first sawed out according to patterns of predetermined shape which leaves them with flat parallel sides and with edges at right-angles thereto. Then these pieces are glued,l cemcnted or otherwise fastened together with the portions thereof which are t'o form the hub in axial alinement with each other and with their parts overlapping vone another predetermined amounts. It is in this condition or stage ofthe method of manufacture tha-t the propeller is shown in Figs. 2 and 3. The shapes of the patterns and the amounts of this overlap are first carefully figured and plotted on drawings from which they may be transferred to wood or other.V

Specification of Letters Patent. i Patentgd July 20, 1915.,

.Application led J une 4, 1910. Serial No. 564,964.

material of which the propeller is to be these pieces have been cut are such as to cause the lines of intersection between adjacent layers v to be the desired lines of the finished propeller taken at different horizontal sections.

I have shown in the first three figures of the drawings a propeller constructed of four flat strips, although a greater or less number may be used if desired. The upper one of these strips is designated by 12, the neXt by 13, the neXtby 14, and the bottom one by 15. vThe line of intersection. between the pieces 12 .and 13 on one side is` designated by 16, and that on the other-side by 17. The

line of intersection between the pieces 13 and 14 on one side is designated by 18 and that von the other side by 19.' The-line of intersection between the pieces 14 and 15 on one side is designated by 20 and that on the other l side by 21. Now that part of each block or layer which projects above the lines 16, 18

and 20 is cut away, leaving a surface, a secline 22. This, then, will leave a surface of the desired shape which may be quired pitch, or which may be of other form if preferred. Similarly,

and that Athese required shapes may be accurately reproduced in the finished article.

made. Now the peculiar shapes into which .tion of which is represented by the broken l that of a f portion of -a true helicalscrewl of the rethe part of each block or layer which'projects below the line 23, which is drawn to intersectthe lines 17,

cut away, leaving the'other y The next step in the construction of the v propeller is to slip over their shaped blades bands of textile material such, for'example,

as stockinet which are designated in the drawings by thel numeral 30. These are preferably continuous bands open at the ends such as I have shown in section in Fig. 5 and about a portion of the left-hand blade of the propeller shown in Fig. 1, and also about the blades of the propeller shown in Fig. 4. These bands may be made considerably smaller than. the blade, so that they must be stretched in putting them in place. It is well within the scope of this part of my invention to have these bands closed at their outer ends, and so woven as to fit snugly over the outer portions of the blades, orover the entire blade if desired, as is shown in section around the righthand blade of the propeller in F ig. l and designated by A. The textile bandis then oemented to the propeller, and the whole is varnishcd, or the varnish alone may be depended upon to hold the band against the surface of the propeller and to prevent its slipping off. These textile bands 30 may also be applied to solid propellers of wood or other fibrous material such as that shown in Fig. 4, the blades of which are designated by 11A. The wood of this propeller also has its grain running longitudinally. The effect of this textile band in any case is to prevent the strips of the propeller or the grain of the wood from splitting apart when it is subjected to strains which come upon it, as

`when it is rotated at high speeds, 'and very materially strengthens the structure.

lVhat I claim is.-

1. The herein described method of making propellers `which consists in cutting a plurality of strips to desired shapes, fastening said strips together in such predetermined relations "that the lines joining the intersections of said strips, in any plane Cutting said strips at right angles, are either one or both curved lines, and cutting away those portions of the strip which project beyond their lines of intersection.

2. The herein described method ofy making propellers which consists in cutting a pluralty of flat strips of wood, with their grain longitudinally disposed, to desired shapes, fastening said strips together in predetermined relations that the lines .of inter'- section between the edge o'f each strip and its adjoining strip are either one or both f curved lines, and cutting away those portions of the strip which project beyond the curved surface joining their lines of intersection.

3. The herein described vmethod of mak` ing propellers which consists in ycutting a plurality of flat strips of different kinds of wood, with their grain longitudinally disposed, to desired shapes, fastening said strips together in such predetermined relations with strips of unlike kinds of wood adjacent to one another that the lines joining the intersections of said strips in any plane cutting said strips at right rangles, are

CIT

either one or both curved lines, and cutting away those portions of the strip which project beyond planes passing through their lines of intersection.

4. lllhe herein described method of making propellers which consists in cutting a plurality of strips to desired shapes, fastening said strips together in such predetermined relations that the lines joining the gether in such predetermined relations that the lines joining the intersection of the edges of the several strips with their adjacent strips are either one or both curved lines with strips of unlike kinds of wood adjacent to one another, cutting away those portions of the strips which project beyond their lines of intersection, and covering parts of said propeller with an endless band of stretchable textile material.

6. A. propeller having its blades constructed of a plurality of longitudinal layers of fibrous material, andendless bands of stretchable textile material placed transverseiy across said blades whereby the cord, warp and Woof of said textile material will be in direct tension and permanently affixed thereto.

7. A propeller blade consisting of a plurality of layers of wood each layer being cut to a shape whereby one edge on each side corresponds to the shape of the finished surface of the propeller at the intersection'of the plane of that layer and so cut that the line joining the intersection of adjacent layers, in a plane cutting said layers at right angles, are either one or both curved-lines.

8. A screw propeller comprising a plurality of laminations of wood each extending from one Ablade through the hub to a diametrically opposite blade, each lamination being cut to a predetermined outline, symmetrical about its middle and the outline of each lamination being such that the edge on one side is a curve which constitutes an element in the curved surface of the finished propeller, whereby the contour ofthe curved surface of the propeller is determined by a plurality of such intersections between adjacent laminations, and the entire surface predetermined so that the cutting away of the surplus ledges on each lamination produces an exact predetermined shape of completed propeller.

In testimony whereof ll have signed my name to this specification in the presence of two subscribing witnesses.

ARTHUR HUGO ECU; GIBSON.

Witnesses: j

ERNEST W. MARSHALL, ELLA Toon. 

